• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.682-685
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• 2003

In this paper, we propose the method to measure the Young's modulus of carbon nano tube which was manufactured by chemical vapor deposition. We also made the tungsten tip by electrochemical etching process and the carbon nano tube which was detangled through ultra-sonication with isopropyl alcohol was attached to the tungsten tip. This tip which was composed of tungsten tip and carbon nano tube can be used in Young's modulus measurement by applying DC voltage with counter electrode. The attachment process and measurement of the deflection of carbon nano tube was done under optical microscope.

• 한국분말재료학회지
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• 제10권1호
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• pp.1-5
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• 2003

Nano-sized WC powders were synthesized by vapor phase reaction using the precusor of tungsten ethoxide under helium and hydrogen atmosphere. The phases of the powder were varied with reaction Bone and gas flow rate. The powder size was about 30nm in diameter, and the tungsten carbide powder was coated by carbon layer. The synthesis of nano-sized WC powders was promoted as the hydrogen gas flow rate became higher. Inversely, tungsten oxide was formed by increasing the flow rate of helium gas. The synthesized powders were analyzed by XRD, FE-SEM, carbon analyzer etc.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2004년도 International Symposium on Powder Materials and Processing
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• pp.50-51
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• 2004

• 마이크로전자및패키징학회지
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• 제13권3호
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• pp.13-17
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• 2006

밀도가 높고 주기적인 배열의 기공과 나노패턴이 된 텅스텐 나노점이 실리콘 산화물/실리콘 기판위에 형성이 되었다. 기공의 지름은 25 nm이고 깊이는 40 nm 이었으며 기공과 기공 사이의 거리는 60 nm이었다. nm 크기의 패턴을 형성시키기 위해서 자기조립물질을 사용했으며 폴리스티렌(PS) 바탕에 벌집형태로 평행하게 배열된 실린더 모양의 폴리메틸메타아크릴레이트(PMMA)의 구조를 형성했다. 폴리메틸메타아크릴레이트를 아세트산으로 제거하여 폴리스티렌만 남아있는 건식 식각용 마스크를 만들었다. 실리콘 산화막은 불소 기반의 화학반응성 식각법을 이용하여 식각했다. nm크기의 트렌치 안에 선택적으로 증착된 텅스텐 나노점을 만들기 위해서 저압화학기상증착(LPCVD)방법을 이용하였다. 텅스텐 나노점과 실리콘 트렌치의 지름은 26 nm 와 30 nm였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.37-42
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• 2007

We present a powder injection molding technique of fabricating cemented tungsten carbide(WC) balls for milling and dispersing nano-powder in this paper. The conventional powder metallurgy approach is investigated to reveal its drawbacks of density non-homogeneity. New procedures of powder injection molding for the homogeneous high-precision WC balls, involving the binding process, powder injection molding process and sintering process, are presented in detail. Each process is investigated empirically and numerically to obtain its engineering information, which can used for process optimization.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.377-378
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• 2006

Thermal management technology is a critical element in all new chip generations, caused by a power multiplication combined with a size reduction. A heat sink, mounted on a base plate, requires the use of special materials possessing both high thermal conductivity (TC) and a coefficient of thermal expansion (CTE) that matches semiconductor materials as well as certain packaging ceramics. In this study, nano tungsten coated copper powder has been developed with a wide range of compositions, 90W-10Cu to 10W-90Cu. Powder technologies were used to make samples to evaluate density, TC, and CTE. Measured TC lies among theoretical values predicted by several existing models.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.362-363
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• 2006

Nano-structured tungsten carbide compacts with cobalt matrices (WC-Co) offer new opportunities for achieving superior hardness and toughness combinations. A unified modeling and simulation tool has been developed to produce maps of sintering pathways from nanocrystalline WC powder to sintered nano-structured WC-Co compacts. This tool includes (1) die compaction, (2) grain growth, (3) densification, (4) sensitivity analysis, and (5) optimization. All material parameters were obtained by curve fitting based on results with two WC-Co powders. Critical processing parameters are determined based on sensitivity analysis and are optimized to minimize grain size with high density.

• 한국자기학회지
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• 제15권2호
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• pp.130-132
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• 2005

Tungsten carbon nitride (W-C-N) thin films were produced by reactive radio frequency (RF) magnetron sputter-ing of tungsten in $Ar-N_2$ gas mixture. The effects of the variation of nitrogen partial pressure on the composition, and structural properties of these films as well as the influence of post-deposition annealing have been studied. When $La_{0.67}Sr_{0.33}MnO_3$ was coated on the W-C-N/Si substrate, coercivity ($H_c$) and magnetization at room temperature shows 58.73 Oe, and 29.4 emu/cc, respectively. In order to improve the diffusion barrier characteristics, we have studied the impurity behaviors to control the ratios of nitrogen and carbon concentrations.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.386-386
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• 2013

반도체 소자의 소형화, 고집적화로 박막의 다층화 및 선폭의 감소 등의 복잡한 제조 공정이 불가피하고, 따라서 공정 중 실리콘 웨이퍼와 금속 박막사이의 확산을 방지하기 위한 많은 연구가 이루어지고 있다. 하지만 현재까지의 연구는 확산방지막의 nano-mechanics 특성 분석에 대한 연구는 전무하다. 본 논문에서 tungsten (W)을 주 물질로, nitrogen (N)을 첨가한 확산방지막을 질소 유량을 2.5, 5, 7.5, 10 sccm으로 변화시켜가면서 rf magnetron sputter 방법으로 tungsten-nitride (W-N) 박막을 증착하였다. 박막의 기본 물성인 증착율, 비저항 및 결정학적 특성을 ${\beta}$-ray, 4-point probe, X-ray diffraction (XRD)를 이용하여 측정하였고, 측정결과 증착 중 질소 유량이 증가할수록 W-N 박막의 비저항은 증가하였고 반대로 증착율과 결정성은 감소하였다. 이는 기존의 연구 결과와 비교하여 일치한 결과로 증착된 박막이 신뢰성을 가짐을 확인하였다. 이후 가장 관심사인 nano-mechanics 특성은 nano-indenter를 이용하여 측정하였다. 측정 결과 시료는 증착 중 질소 유량이 2.5 sccm인 시료를 기준으로 5 sccm 포함된 박막에서 load force-depth 그래프가 급격히 변화하는 경향을 나타내었고, 표면강도(surface hardness)는 10.07 GPa에서 15.55 GPa로 증가하였다. 이후 질소 유량이 7.5 sccm과 10 sccm에서는 12.65 GPa와 12.77 GPa로 질소 유량이 5 sccm 포함된 박막보다 상대적으로 감소하였다. 이는 박막내 결정상으로 존재하는 질소와 비정질 상태로 존재하는 질소의 비율에 의한 것이고, 압축력에 기인하는 스트레스 증가로 판단된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1888-1891
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• 2003

In this paper, we proposed a new method to control the length of carbon nano tube in the single CNT probe. A single CNT probe was composed of a tungsten tip made by the electrochemical etching and carbon nano tube which was grown by CVD and prepared through the sonication. The two components were attached with the carbon tape. Since the length of CNT can not be controlled during the manufacturing, the post process is needed to shorten the CNT. In this paper, we proposed the method of electrochemical process. The process was done under the optical microscope and the results were checked by SEM. The diameter of the carbon nano tube used in this paper was about 130nm because the above process had to be done with the optical microscope. Using the method proposed in this paper, we can control the length of the nano tube tip.